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From: Andreas Leitgeb <avl@logic.at>
Newsgroups: comp.lang.java.programmer
Subject: Re: Thread and synchonized question
Date: Mon, 30 Sep 2019 10:10:42 -0000 (UTC)
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mike <mikaelpetterson@hotmail.com> wrote:
> We have class A with method synchronized connect(int) that calls
> class B that has synchronized connect() (main thread)
> I guess the lock will be on class A?

There are some relevant details missing, so there are two options:
A) either or both of the methods are static, or there are two objects
     one of A and one of B that you call the method on: then the locks
     are independent, and main thread just hold both.
B) One of the methods is just a superclass method, and both "synchronize"s
     address the same object, and the main thread holds that one twice.

> What if class B and synchronized connect()is called by another
> thread ( reconnect thread) I guess lock is on class B.

> So does this mean that both main and reconnect threads can access
> the synchronized connect() on class B?

That can be pretty surely excluded in either of the above cases.